Fluid filters are widely known and used in a variety of systems requiring filtration of a working fluid. After use and wear, many fluid filters eventually must have their filter elements serviced and/or replaced, and many fluid filters themselves must be removed in order to be serviced and/or replaced. Thus, ease and cleanliness of service have been concerns in fluid filter design. Preventing leakage or at least confining leakage has presented challenges in the sealing structure of such fluid filters. In one example shown in FIG. 25, a typical spin-on filter 900 includes a metallic nutplate 914 that typically is employed for allowing unfiltered fluid to flow into opening 922. The unfiltered fluid filters through a filter media 910, and the filtered fluid flows out of opening 920. Such filters generally require a large seal 916 around the outer edge of the housing 912 and between the housing 912 and nutplate 914. An additional seal 918 is further required around the attaching spud and between the spud and the nutplate.
While previous designs have been useful, improvements and modifications can still be made in fluid filter design, for example, at the filter head and attachment interface.